hook checkbox evaluation to Checkbox.length not to VariableName.length.

public/checklist.php

@@ -311,7 +311,7 @@
               forwardingInfo += "&Run_Range="  + runRange;
 
               var temp = '';
-              for (let i = 0; i < arrayLength; i++){
+              for (let i = 0; i < Checkboxes.length; i++){
                 var good = document.getElementById(Checkboxes[i]);
                 var comment = document.getElementById(Comments[i]);
                 if (good.checked == true){